cta-learn-more · Jun 23, 2022

Why Do Babies Cry in Their Sleep? Let’s Find Out!

Baby sleeping in crib – Why Do Babies Cry In their Sleep Hero Image

Have you ever heard your baby crying but found them to still be asleep when you actually check on them? Or perhaps you’ve actually witnessed with your own eyes your baby screaming or crying out while their eyes are still closed? If so, don’t worry — you’re not going crazy!

Crying during sleep is actually a very normal thing that many babies do. However, it’s still useful to understand why this happens and if anything can be done to help your seemingly distressed baby while they should be getting some well-needed rest.

Crying During Sleep vs Waking Up and Crying

Seeing or hearing your baby crying when sleeping can be worrying. Especially when you don’t know the cause of their unhappiness. However, first, remember that crying is merely communication — this is the primary way infants let those around them know how they feel and what they need (whether that’s food, comfort or something else).

The most common reason you’re hearing your child crying when you’ve put them to sleep is they still need something and have woken up crying and are now communicating to others about their needs. As you may have already learned, identifying what is causing your child’s crying involves checking through several potential causes, such as hunger, discomfort, temperature (too hot or cold), dirty nappy and so on.

What’s harder to do is decipher why your baby is crying when they’re still asleep! This is much less common than your little one waking up after being asleep and crying, but it still happens, so don’t be alarmed. Many believe this is caused by nightmares, but as we discuss later, this doesn’t happen until your baby’s brain is more developed.

This behavior may be confusing, but there are a few explanations for why your child will suddenly start crying (or make strange sounds like grunting or screams) while they’re actually still asleep!

Why Babies Cry in Their Sleep

Baby waking up and crying in their sleep at bedtime

There are a few different reasons why babies cry in their sleep. Understanding these can help you know what to look for and how to help your baby.

1. Crying Between Sleep Cycles

It could be as simple as your baby crying between sleep cycles. As adults do, babies sleep in cycles. As they transition from one cycle to another, they pass through a “lighter” kind of sleep and it may be in these moments that they momentarily wake up and cry out before going back to sleep.

During REM sleep (which babies spend more time in than adults due to the frequency that they switch between different sleep cycles), it can be common for them to stir, stretch, jerk, twitch, and even cry out. A sleep cycle for a baby is around 40 minutes and during their brief awakening at the end of each cycle, you may notice them do something strange that will cause you to check on them.

If they’re able to get themselves back to sleep, however, this is a great thing. Self-soothing is an important component in sleep skills development, so we’d caution you to wait and see if your child looks calm and restful after their outburst before you wake them up.

Learn More About Baby Sleep Cycles!

2. Small Pains and Discomfort

Babies experience several small pains and discomforts as part of their natural development. For instance, they’ll feel considerable pain when their first teeth start to emerge. It could be because of this that they’re feeling more sensitive, uncomfortable and fussy — potentially crying or whimpering in their sleep due to the pain.

The pain may not be enough to wake them up completely and if they’re drowsy enough, they may settle down more deeply if you just give them a chance. It’s possible that the rest will do them more good than waking them up and comforting them, but it could be worth talking to a doctor about advice for teething babies.

Read our guide: How to Help Baby Sleep When Teething in 7 Easy Steps

3. Night Terrors?

Nightmares and night terrors are most common between the ages of 3 and 6 years, and most children won’t start until around age 2. As such, a newborn who is crying in their sleep probably won’t be suffering from one of these. Their crying is most likely linked to something else.

If your child is older and you believe they’re suffering from nightmares or night terrors, it might be wise to contact your pediatrician for advice.

Self-soothing is an important component in sleep skills development, so we’d caution you to wait and see if your child looks calm and restful after their outburst before you wake them up.

4. Natural Development

Crying during sleep could just be a cause of brain development, according to the UK National Charity for Pregnancy, the NCT. This means that strange sounds could be caused by “mental leaps” your baby is achieving rapidly during their first months.

Keeping your child safe and healthy is the best thing you can do if there’s no specific issue contributing to their crying at night. As long as you’ve made sure their sleeping environment and routines are 100% baby-suitable and safe, you don’t have to worry about small amounts of crying in their sleep.

Read Our Ultimate Guide for Safe Baby Sleep!

Solutions for Helping Your Crying Baby (While They’re Still Sleeping)

Mother wondering why do babies cry in their sleep while dressing baby

Occasional crying in small doses while sleeping usually isn’t something to worry about seriously. You may naturally want to rescue your child from whatever is causing them to whimper or scream at night, but before you sweep in and wake them up, just wait and watch to see if they’re able to settle themselves back into a state of calm again first.

Waking your baby up could disrupt their sleep more than if you were to let them get on with things. It could also derail their long-term development of sleep skills and self-sufficiency if you keep waking them up every time you hear them cry out during sleep.

Babies learning to sleep still may struggle at times – especially during transitions between sleep cycles — and letting them overcome this challenge alone can give them the training they need to be strong sleepers as toddlers and adults!

Of course, some light whimpering is different from very loud crying and wailing, so we'll let you make your own call about whether your child is really suffering and needs waking up. However, keep in mind that if their pain is considerable enough, they would probably have woken up fully anyway, rather than have gone back to sleep.

With careful attention, you may even be able to decipher the specific kind of cry you’re hearing from your baby, giving you a more targeted way to help them. For instance, are they crying because of hunger? Overheating? Sickness?

A Gentle Awakening

If you decide to wake your little one up because of their crying, keep their awakening gentle. If they need a light feeding, try to keep the disruption to a minimum and place them back in their crib as soon as you’re done, rather than allow them to fully wake up.

Adjusting Bedtime

Bedtime routines are essential for infants. Having a strong pattern to follow each night can help them sleep better and stop them from waking up if they’re feeling any momentary discomfort. Your routine doesn’t have to be complicated or lengthy — the most important thing is that you keep things consistent each night.

Make them More Comfortable

Making sure your baby is 100% comfortable and safe in their crib will help you to worry less about them if you hear them crying every now and then. By ruling out any possible causes of distress, such as uncomfortable bedding, poor clothing choices that are scratchy, or a room that is either too cold or hot, you’ll be less tempted to wake them up and comfort them when they cry out.

How to Help Our Baby Sleep at Night – A Practical Guide

Why Do Babies Wake Up and Start Crying?

Parent wondering why do babies cry in their sleep

If your baby is waking up and crying regularly at night, this is completely normal too. It takes a while for babies to learn how to sleep for long stretches through the night and they’ll often wake up during the night, followed quickly by crying because they’re trying to communicate with adults about how they’re feeling or what they need.

At times, there’s no real message they’re trying to convey and it’s best to let them settle themselves down on their own. However, at other times, there may be specific things that your child needs in order to sleep properly again, whether this is food or just comfort from an adult.

Hunger, overtiredness, pain or discomfort caused by teething or minor illnesses like colds, anxiety and more are all reasons your baby may start crying at night.

How to Help Baby Sleep When Teething in 7 Easy Steps

Potential Reasons Your Baby Wakes Up Crying

Hunger
Tiredness
Needs changing
Needs comfort
Too hot or cold
Illness

Solutions for Helping Your Crying Baby when They’re Awake

The best way to help a baby who has woken up crying is to quickly figure out what they need. By giving them a feed, some attention or adjusting the room temperature, it may be possible to get them to sleep again.

If there’s no apparent reason for your child’s crying and you’ve checked that they are 100% safe and healthy, it may just be time to start sleep training your little one — encouraging them to become sleep independent and soothe themselves back to sleep. By rushing in too quickly and too often, your child may become too reliant on your help so they should be given the chance to persevere alone.

A Checklist for Crying Babies

Have you checked that it’s not too hot or cold? Sometimes when transitioning between seasons, the temperature can change quickly without you realizing and as babies are sensitive to this, you’ll need to be careful about adjusting things like heating settings or air conditioning.

Is your baby wearing the right clothes? A baby’s clothes can contribute to their ability to sleep massively and many babies will rely on the swaddle to give them the womb-like cozy comfort they crave in order to sleep. And if you’ve dropped the swaddle because your little one is too old (over 2 months), they may find it hard to sleep because of this. In these situations, it’s recommended that you explore swaddle transition options, such as our Zipadee-Zip!

Are there any noises or distractions affecting your baby’s sleep? Even the smallest noises, vibrations or light from gadgets or outside can disrupt your baby’s sleep. Try to cut these out so your baby can sleep soundly.

See Our Zipadee-Zip Collection

Strengthen Nighttime Routines

A strong nighttime routine can help with many sleep-related issues, such as your child not sleeping in the first place or regularly waking up and crying. If your child is well-fed, relaxed and cozy from their bedtime ritual, they’ll be in a much better state to sleep through the night.

To prevent them from crying out whenever they wake up, consider optimizing the set of steps you take with your baby each night.

For more on this topic, check out our guide: Baby Crying at Night: Causes and Solutions

Do I Need to Contact a Doctor?

Doctor examining why baby cries in their sleep

We understand that hearing your baby crying at night, either while they sleep or after they wake, can sometimes be worrying. And if there is something about your little one's behavior that’s giving you cause for concern, or if you suspect their reason for crying is because of an illness or related health issue, consult your doctor.

If you’re still thinking “but why do babies cry in their sleep?” your child’s pediatrician may help you achieve more clarity about what’s happening at their specific stage of development — whether they can explain a specific use for your little one or simply reassure you that everything your child is doing is completely normal.